Lock



March s', 192s. 1,661,477

' F. J. HELMUTH LOCK original Filed March 17. 1926 ,5w/w J /ffL Mar/f.

l N VEN TOR l Mmm ATTORNEY `Patented Mar. 6, 1928.

. UNITED STATES PATENTon-ICEV FRANK J. HELMUTH, oFoAx'LAND, CALIFORNIA.

LOCK. v p

Original application` led March 17, 1926, Serial No. 95,340. Divided and this application led July 8l,

f 1926. serial ita-125,669.

`The present invention relates to improvement in locks and has particular reference to a door lock. The principal object of the invention is to provide a lock of the `charn acterdescribed that is particularly well constructed and difficult to-open without the aid of a key made for the same.

The present yapplication `is divisional to application Serial No. 95,340, filed March 17, 1926. i

The preferred form of my invention is illustratedin the accompanying drawing in whichh Y Figure l shows an axial section thru my x lock,

Figure 2 a ,transverse section thru lthe same,

Figure 3 an end view of the tumbler arrangement as viewed` from the real',

Figures 4 and 5 detailed views graphically illustrating the cooperation between the key andthe tumbler., Y.

Figure 6 a longitudinal section thru a tubular element cooperating with the tumbler arrangement, and

Figure 7 an end view of the latter.

While I have shown only the preferred form of my invention, it shouldA be understood that various changes or modifications may be made within the scope of the claims hereto attached Without departing from the spirit of the invention. f

In its preferred form, my look comprises a tumbler arrangement accommodated in the tumbler'housing 1 and adapted to be used in connection with the bolt operating mechanism arranged in a rectangular flat case 2, which latter may be inserted into the edge of a door in a manner well known in the art. The housing l is adapted for in- Y serton thru a transverse hole and to be threaded int-o the case 4after the latter has been inserted as shown at 3 in Figure 1. The front end of the housing is provided with a slight conical flange 4 and receives before insertion, a conical ring 6 adapted to Y bear on the plate 7 customarily arranged on doors in combination with locks of this character. The housing is firmly held against rotary motion by means of a set screw introduced from the edge of the door thru a hole in the plate 9 and this set screw extends thru a tube 1l disposed on the inside of the housing so that this tube is also held against rotary motion. The tube is. provided with a plurality of longitudinal slots 12 connect,- lng each with a transverse slot'l. Acylinf der `14 is revolvable in .this tube ll, .but is held lagainst endwise motion by means ,of u lflange 16 bearing yon `the outer end of the 50 tube 11 andl seated in a recess 17 inthe housing and at the other-end by a plate 18 .se

cured to the cylinder by means .of screws 19.

The cylinder is formed with 4a plurality of'radial yslots 21 adapted to sldafbly receive C# Iregistering flat .tumblers 22 having pins 23 ,projecting forwardly therefrom and extending into small holes 24 Vthrough which prongs 26 of ka key 27 may be inserted. The length of the pins 23 and. the prongs 26 is such that .7,9

when `the key 27 is fully inserted, the pins y23 and, with them, the ,tumblers -22 are lpushed backwards sufficiently far :to ,allow ,outward vprojections 28 extending from the tumblers into the longitudinal slots 12pt@ :7.5

register `with the transverse slots 13 and :t0 be pushed -thereinto by a revolving motion ofthe key. The lattery is formed with a central guiding member 29 adapted for inser..

tion in a perforation 31 in the cylinder for 80 steadying the key. The guide member is preferably notched as shown in 32 to allow a spring 33 in the perforation 31 to catch therein. Springs 34 guided by pins 36 tend to push the tumblers toward the front while a spiral 37 accommodated in a recess 38 within the'cylinder 14 tends to return the cylinder to its initial position from a rota-ry excursion. The rotary motion of the cylinder is limited by a pin 35 extending from 90 therear edge of the housing and riding in a peripheral recess 4() formed in the plate 18.V A retractable dog 41 projects from the plate 18 and has a spring 42 associated therewith tending to force the same outwardly. This dog is used for transferring rotary motion from the cylinder 14 to the` bolt operating mechanism, which latter is shown in detail in theco-pending application of which this forms a subdivision and which includes as 'actuating member a ratchet 43 mounted co-axially with the cylinder and allowing thedog 41 to ride thereon. The ratchet is held againstl backward motion by a pawl 44 engaging with another 106 steep face thereof for the next turn. The

operation of my locking device as far as described in the present application is as follows:

To operate the same, a key is inserted which pushes the tumblels backward over the resistance of the springs 31 until the projecting prongs 28 register with the transverse slots 13 in the tube ll and allow the cylinder to be turned against the opposition of the spring,r 37, the turning movement be ing limited by the pin This turning movement -is transferred to the ratchet 43 by the dogg' 41 and causes the ratchet to advance by the length of one tooth. As the operator releases the key, the cylinder 14 returns to its initial position due to the action ot the aprilier 37 while the dog 4l climbs over the slant-ing,- 'tace 47 ot the next tooth for engagement with the steep face 48 thereof. The return of the cylinder to its initial position causes the projections 28 to again regiSter with the longitiulinal Slots in the tube 11 and allows the tumblers to return to their initial position due to the action ot' the springs 34.

I claim:

l. In a lock ofi the character described, a stationary element, a member mounted therein with freedom of rotary motion through a limited are and having yielding' means associated therewith urging the latter to an initial position, means normally lockingr the member in an initial position made to yield to the insertion of a key, and a spring' pressed plunger projecting.r eccentrically trom an end face of the member adapted to ride on a ratchet for advancing the same when the member is turned in one direction and takingr a new bite when thc member ifs turned in the opposite direction.

2. ln a lock of the character described` a stationary element, a member rcvolvable relative thereto, means normally lockingF the member to the element yielding;r to the inscrtion of a key and a spring pressed plunger projecting ecccntrically from an end t'ace of the member adapted to ride on a ratchet for advancing' the same when the member is turned in one direction and for taking.r a new bite when the, member is tul'ncd in the, opposite direction.

3. In a lock ot the character described. :i stationary clement, a member rcvolvable relative thereto, and a spring-pressed plunger projectingeccentrically from said nicmber adapted to ride in a ratchet.

L In a lock ot' the character described, i cylindrical body, a plurality ol longitudinally movable tumblers therein, a bore in the cylindrical body for the reception of a guide element on a key, said movable tumblers beingr adapted to be pushed by prongs on the key, and spring means provided in the bore bearing' on the guide element tor yieldingly holding the. same in place.

ln testimony whereof I atiix my signature.

,FRANK J. ll ELMUlI'I. 

